Refer to the exhibit.
Router1# show ip bgp
BGP table version is 4, local router ID is 192.168.1.1
Status codes: s suppressed, d damped, h history. * valid. > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 192.168.10.0/24 192.168.1.2 0 0 65525 i
> 192.168.3.0/24 192.168.2.2 0 0 65535 i
* 192.168.3.0/24 192.168.4.2 0 0 65545 i
*> 192.168.20.0/24 0.0.0.0 0 32768 i
Which attribute can router 1 alter so that only other iBGP peers prefer to use 192.168.4.2 as the next hop for route 192.168.3.0/24?